Series of proposed style changes

Implemented suggestions from this [comment](https://github.com/openframeworks/ofBook/pull/68#issuecomment-53199992):
- Chapter container is bumped up in size.  It is set to 80% of it's parent (the fluid bootstrap span9 div), with a max-width of 800px.
- Hyperlinks target new windows and are styled with the openFrameworks pink color.
- Inline code styling was toned down.
- Images are allowed to be as big as the chapter container.  Captions are pushed off to the right of the chapter container.